摘要:为实现采用气流粉碎技术制备羟基Schiff碱,以高速气流为载体,使羟基芳香醛和对氨基苯甲酸在粉碎腔中摩擦活化,再通过反复撞击腔体内的固定靶产生巨大的能量交换从而诱导反应的发生。利用傅立叶变换红外光谱、核磁共振、质谱等现代测试技术表征3种含羟基Schiff碱结构,采用半经验计算方法PM3获取原料的前线轨道能量,并对产物几何结构进行优化。结果表明:羟基芳香醛与对氨基苯甲酸反应困难程度随2,3,4-三羟基苯甲醛、间羟基苯甲醛、对羟基苯甲醛依次增大。其理论计算结果与实验测试最佳制备工艺一致。
关键词: 气流粉碎;Schiff碱;结构优化:
Abstract: In order to prepare Schiff bases with hydroxyl using gas flow crushing, the mixture including p-aminobenzoic acid and aromatic aldehyde with hydroxyl were fractioned, activated, and the supersonic speed airflow acted on aromatic aldehyde with hydroxyl and p-aminobenzoic acid in reaction zone. Then the mixture could react according to the exchange of rapid energy through impacting on the certain target. The structures of three Schiff bases with hydroxyl were characterized by Fourier transform infrared spectroscopy, 1 H nuclear magnetic resonance and mass spectrometer. Frontier molecular orbital energy for the reactants employed and geometric structure were investigated by semiemperical calculations method PM3. The calculation results showed that the reaction difficulty of aromatic aldehyde with hydroxyl and p-aminobenzoic acid was following: 2, 3, 4-trihydroxyb - enzaldehyde, m-hydroxybenzaldehyde, p-hydroxy benzaldehyde. The results also showed the consistency between theoretical and practical reaction.
Keywords:gas flow crushing; Schiff base; optimized structures